In a manufacturing process of a semiconductor device, a liquid processing such as wet etching or chemical liquid cleaning is performed on a substrate such as a semiconductor wafer by supplying a processing liquid onto a surface of the substrate while rotating the substrate around a vertical axis. Though the supply of the processing liquid onto the substrate is generally performed by a movable nozzle held by a nozzle arm, it may be performed by an outer nozzle provided at an outside of an outer edge of the substrate (see, for example, Patent Document 1).
The outer nozzle is used to supply the processing liquid to a central portion of the substrate to suppress the central portion of the substrate being rotated from being dried when the movable nozzle is unable to supply the required processing liquid onto the central portion of the substrate. The outer nozzle is immovably fixed to the outside of the outer edge of the substrate. Therefore, an arrival position of the processing liquid discharged from the outer nozzle is entirely determined based on a discharge flow rate of the processing liquid (force of the liquid). For the purposes of suppressing the substrate from being dried, the processing liquid discharged from the outer nozzle is required to cover the central portion of the substrate. For this reason, the flow rate of the processing liquid supplied onto the substrate from the outer nozzle cannot be changed flexibly as required.